The present invention relates to a gas scrubbing system for removing gaseous pollutants, particularly hydrocarbons, from a moving stream of heated gas by means of temperature reduction and resultant condensation of the pollutants. Although there are scrubbing devices known to the art for cleansing material from a moving stream of gas, most of the known prior art devices are capable of removing only particulate matter and all are relatively ineffective in removing vapors. Examples of known prior art scrubbing devices include those disclosed by Bauer U.S. Pat. No. 1,110,868, Frey U.S. Pat. No. 1,999,589 and Weits et al U.S. Pat. No. 2,409,088, each of which includes a chamber through which a stream of gas is moved, circulating means within the chamber for imparting cyclonic movement to the gas, and a plurality of spray heads also positioned within the chamber for producing a water spray through which the gas must pass before it is vented to the atmosphere. Particulate matter carried by the gas is contacted by the water spray and carried out of the chamber with the spray water. These devices are relatively ineffective in removing non-particulate or gaseous matter from the moving gas stream because of their reliance solely upon mechanical contact between the spray water and the material to be removed, and their failure to incorporate features maximizing the transfer of heat from the gas to the spray water and the reduction of the temperature of the gas.
A significant disadvantage of several known prior art devices, in addition to their inability to efficiently remove non-particulate matter from gas streams, is that the water used to create the water spray is simply discharged as waste water once it has passed through the device. Those known prior art devices that do recirculate the water to the spray heads for reuse do so on an inefficient individual basis requiring a separate water circulation system for each gas-cleansing device. Examples of such devices include those disclosed by Tailor U.S. Pat. No. 3,050,919, Wisting U.S. Pat. No. 3,336,733, and Hoad U.S. Pat. No. 3,841,060, each of which includes a water recirculating system and an individual separator of a simple design better adapted to the relatively easy task of removing particulate pollutants from the water than the more difficult task of removing condensed gaseous pollutants.